1975 1500 mid range bog

[procraftguy]

Fresh rebuit powerhead with about 2 hrs on it cant get it too run very well starts like a champ idles smooth but high 1000 caint get lower it just dies put it in gear it will troll around all day go to theottle up its 50 50 if it dies it dogs down then races right out to 4500 rpm runs there great wot is about 5200 wich is low for this motor thats trimed out as well timming is 4 with primary just starting to move and 21 max advance carbs redone reeds and seals good no water on plugs good fuel pump one note if i touch the idle adjustments it dies its real fussy if i do get it running lower on hose at lak i have to put it back to even start iv searched threads and seen alot of same and ideas to fix but no one saying they fixed it so here i am i will be re linking and syncing for 10th time need advice were else to look

 

[MTboatguy]

Were the carbs rebuilt as well? Sounds like you have dirty carbs that are bogging on the transition from low speed to high speed, if the carbs were not rebuilt or at least cleans, I would do that before anything else.

 

[procraftguy]

Yes i rebuilt the float bowls had plastic needles replaced and new floats cleand everything else up as it looked good i was thinking of pulling out the idle adjust screws and spraying som cleaner in there i also unhooked the back drag hose on top

 

[Chris1956]

New inlet needles were neoprene tipped- stainless steel, with brass seats, right? You cleaned the idle passages, when you have the carbs off right? No need to remove the idle mixture needles again. You set the correct float heights?

If you said yes, than two things need your attention. Adjust the idle stop screw to lower the idle to 900RPM, if she will run at that RPM. Next adjust the throttle cable to push the push the throttle up against the stop. Now open the top idle mixture screw 1/8 turn and see if she accelerates better. Repeat with middle screw and then bottom screw, testing acceleration after each adjustment.

I would reconnect the back drag hoses. Disconnecting them adds more air to the mixture, leaning it out. That is not good. Plug them if you like.

 

[procraftguy]

Thank you chris i was under the impression u could just unhook the hoses as they caused lean condition i will plug them i noteced in the manual the idle passge tube i didnt clean that when i had it tore down guess ill be ording a gasket kit and cleanning those ill post back either way

 

[merc850]

Set the low speed needles to 1 1/4 turns out; then with the motor warmed up running in F in the lake at 1200 rpms turn the low speeds one at a time slowly until the motor runs smooth then turn them out a bit more to get a smooth take-off.

 

[procraftguy]

Changed jet size up 2 as suggested by guy at marina and its running like a raped ape still only 5100 wot so i just order a 4 blade 13x 17 pitch vortex prop too try out hope that gets me up there ty all